In medical testing, photometric (light) measurement of photoluminescence, absorbance, or the like may be used as a mechanism to determine a measured characteristic of a test sample (e.g., a biological fluid). For example, in some automated testing systems (e.g., clinical analyzers) reaction vessels, such as cuvettes, flow-through vessels, sample cups, vials, and the like, may receive a biological fluid (e.g., blood, blood plasma, spinal fluid, cerebral fluid, interstitial fluid, urine, or the like), possibly containing one or more reagents or other liquids such as purified water (collectively referred to herein as a “test sample”). The test sample in the reaction vessel may be held within an illumination system. Light emissions from a light source may be projected through the test sample, and the light emanating from the test sample may be detected by one or more photodetectors. From the detected light signals, a characteristic property of interest may be determined (e.g., absorbance, luminescence, or the like) at one or more discrete emission wavelength ranges. However, existing light intensity measurement apparatus and systems may suffer from relatively high signal-to-noise ratio.
Accordingly, apparatus, systems, and methods that may improve an accuracy of such multi-channel light measurements are desired.